These booties are sleek, form-fitting, and aerodynamic. The double Velcro rear closure makes them easy to put on and take off. They are warm, and do a good job keeping the wind out. Keeping water out is a different story. They work well in a light rain or when the roads are wet, but they are definitely not waterproof. They will soak through in less than an hour in a heavy rain. In addition, they seem a little delicate - the bottom of one is already fraying around the cleat opening (I use Shimano SPD road cleats), and I've only had them for a few months.
I was looking for a more aero and form-fitting alternative to my bulky but definitely waterproof Gore Tex booties. These work well on damp roads or in a light rain, but when it's really coming down - which it often is in Portland - I'm sticking with the Gore Tex clunkers. They may be bulky, but they are more effective in really wet conditions. Plus, they are more durable. I'll go with the sleeker Pearl Izumis in milder conditions.